Ion manipulation device to prevent loss of ions

ABSTRACT

An ion manipulation method and device to prevent loss of ions is disclosed. The device includes a pair of surfaces. An inner array of electrodes is coupled to the surfaces. A RF voltage and a DC voltage are alternately applied to the inner array of electrodes. The applied RF voltage is alternately positive and negative so that immediately adjacent or nearest neighbor RF applied electrodes are supplied with RF signals that are approximately 180 degrees out of phase.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.14/292,448, filed May 30, 2014, which is a continuation-in-part of U.S.application Ser. No. 14/146,922, filed Jan. 3, 2014, now issued as U.S.Pat. No. 8,835,839, which claims the benefit of U.S. ProvisionalApplication No. 61/809,660, filed Apr. 8, 2013, the disclosures of whichare hereby incorporated by reference herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

The invention was made with Government support under ContractDE-AC05-76RLO1830, awarded by the U.S. Department of Energy. TheGovernment has certain rights in the invention.

TECHNICAL FIELD

This invention relates to ion manipulations in gases. More specifically,this invention relates to the use of RF and/or DC fields to manipulateions through electrodes, and building complex sequences of suchmanipulations in devices that include one or more such surfaces andstructures built upon the surfaces.

BACKGROUND OF THE INVENTION

As the roles for mass spectrometry and other technologies that involvethe use, manipulation or analysis of ions continue to expand, newopportunities can become limited by approaches currently used forextended sequences of ion manipulations, including their transportthrough regions of elevated pressure, reaction (both ion-molecule andion-ion), and ion mobility separations. As such manipulations becomemore sophisticated, conventional instrument designs and ion opticapproaches become increasingly impractical, expensive and/orinefficient.

SUMMARY OF THE INVENTION

The present invention is directed to devices and methods of manipulatingions in gases. In one embodiment, an ion manipulation device isdisclosed that is essentially lossless and allows extended sequences ofion manipulations. The device includes a pair of surfaces and in which apseudopotential is formed that inhibits charged particles fromapproaching either of the surfaces, and the simultaneous application ofDC potentials to control and restrict movement of ions between thesurfaces.

In one implementation this involves two substantially or identicalsurfaces that have an inner array of electrodes, surrounded by a firstouter array of electrodes and a second outer array of electrodes. Eachouter array of electrodes is positioned on either side of the innerelectrodes and contained within—and extending substantially along thelength of—each parallel surface in a fashion similar to the inner arrayof electrodes. The DC potentials are applied to the first and secondouter array of electrodes. The RF potentials, with a superimposedelectric field, are applied to the array of inner electrodes.

The superimposed electric field may be a static or dynamic electricfield. The static electric field may be, but is not limited to, a DCgradient. The dynamic electric field may be, but is not limited to, atraveling wave.

In one embodiment, the electrode arrangements on the two surfaces areidentical, such that similar or identical voltages are applied to both.However, the exact arrangement of electrodes can differ, and the precisevoltages applied to the two facing surfaces can also differ.

The pair of surfaces may be substantially planar, substantially parallelor parallel, or not flat.

In one embodiment, the RF potentials are applied along with the DCpotentials on the first and second outer electrode arrays. In anotherembodiment, the RF potentials are applied to only one of the twosurfaces. In another embodiment, the RF potentials are applied to bothof the surfaces.

In one embodiment, the electric field in all or a portion of the devicemay be replaced with a gas flow to move ions in the direction of the gasflow.

In one embodiment, the RF on at least one inner electrode is out ofphase with its neighboring inner electrode. In one embodiment the RF oneach electrode is phase shifted with its neighboring inner electrode toform a repulsive pseudopotential. In one embodiment, the RF on eachelectrode is approximately 180 degrees out of phase with its neighboringinner electrode to form the pseudopotential.

In one embodiment, the array of inner electrodes comprises at least twoelectrodes on the pair of surfaces. In another embodiment, the firstouter array of electrodes and the second outer array of electrodes eachcomprise at least two electrodes on the pair of surfaces. The device caninclude insulating material or resistive material between theelectrodes.

The RF voltage applied to the electrodes is between 0.1 kHz and 50 MHz,the electric field is between 0 and 5000 volts/mm, and operatingpressures from less than 10⁻³ torr to approximately atmospheric pressureor higher.

In one embodiment, the electrodes are perpendicular to at least one ofthe surfaces. In an alternative embodiment, the electrodes are parallelto at least one of the surfaces. The electrodes may comprise a thinconductive layer on the surfaces.

In certain embodiments, the device comprises multiple pairs of surfacesand allows transfer of the ions through an aperture to move betweendifferent pairs of surfaces.

The electrodes on the pair of surfaces may form one or more differentconfigurations. These configurations include, but are not limited to,the following: a substantially T-shaped configuration, allowing ions tobe switched at a junction of the T-shaped configuration; a substantiallyY-shaped configuration, allowing ions to be switched at a junction ofthe Y-shaped configuration; a substantially X-shaped or cross-shapedconfiguration, allowing ions to be switched at a junction of one or moresides of the X-shaped or cross-shaped configuration; and/or asubstantially multidirectional shape, such as an asterisk (*)-shapedconfiguration, with multiple junction points, allowing ions to beswitched at a junction to one or more sides of the configuration.

In one embodiment, the electric field allows the ions to move in acircular-shaped path, rectangular-shaped path, or other irregular path,to allow the ions to make more than one transit and, as one example,achieve higher resolution ion mobility separations.

The space between the surfaces may be filled with an inert gas or a gasthat ions react with ions.

Stacks of cyclotron stages may be used with the device to, for example,allow different ranges of ion mobilities to be separated in differentcyclotron stages, and in sum cover the entire range of ions in amixture.

The electric fields can be increased to cause ions to react ordissociate.

The device may be coupled to at least one of the following: a chargedetector, an optical detector, and/or a mass spectrometer.

In one embodiment, the device can be fabricated and assembled usingprinted circuit board technology and interfaced with a massspectrometer.

The device can be used to perform ion mobility separations and/ordifferential ion mobility separations (e.g., FAIMS).

Ions may be formed outside or inside the device using photoionization,Corona discharge, laser ionization, electron impact, field ionization,electrospray, or any other ionization technique that generates ions tobe used with the device.

In another embodiment of the present invention, an ion manipulationdevice is disclosed. The device includes a pair of substantiallyparallel surfaces. The device further includes an array of innerelectrodes contained within, and extending substantially along thelength of, each parallel surface. The device also includes a first outerarray of electrodes and a second outer array of electrodes, eachpositioned on either side of the inner electrodes, contained within, andextending substantially along the length of, each parallel surface,wherein a pseudopotential is formed that inhibits charged particles fromapproaching either of the parallel surfaces. The device also includes aRF voltage source and DC voltage sources, wherein a first DC voltagesource is applied to the first and second outer array of electrodes andwherein a RF frequency, with a superimposed electric field, is appliedto the inner electrodes by applying a second DC voltage to eachelectrode, such that ions move between the parallel surfaces within anion confinement area in the direction of the electric field or can betrapped in the ion confinement area.

In one embodiment, the RF frequency applied to the electrodes is between0.1 kHz and 50 MHz. The RF peak-to-peak voltage is approximately 10 to2000 volts. The electric field is between about 0 and about 5000volts/mm, and the pressure is between 10⁻³ torr and atmosphericpressure.

In one embodiment, one or more of the electrodes has 0.5 to 10 mm relieffrom the surface, so that degradation of device performance due tocharging of the surfaces between electrodes is prevented.

In another embodiment of the present invention, a method of manipulatingions is disclosed. The method includes injecting ions between a pair ofsubstantially parallel surfaces, wherein each pair of parallel surfacescontains an array of inner electrodes and a first and second array ofouter electrodes on either side of the inner electrodes. The methodfurther includes applying RF fields to confine the ions between thesurfaces. The method also includes applying a first DC field to theouter electrodes equal to or higher than a second DC field applied tothe inner electrodes to confine ions laterally. The method also includessuperimposing the second DC field on the RF field to further confine andmove the ions along in a direction set by the electric field.

In one embodiment, the method further includes transferring the ionsthrough an aperture in at least one of the pairs of parallel surfaces,wherein the ions travel to between another pair of parallel surfaces.

In another embodiment of the present invention, an ion manipulationdevice is disclosed. The device includes multiple pairs of substantiallyparallel surfaces. The device further includes an array of innerelectrodes contained within, and extending substantially along thelength of, each parallel surface. The device also includes a pluralityof outer arrays of electrodes, wherein at least one outer array ofelectrodes is positioned on either side of the inner electrodes. Eachouter array is contained within and extends substantially along thelength of each parallel surface, forming a potential that can inhibitions moving in the direction of the outer array of electrodes, and whichworks in conjunction with a pseudopotential created by potentialsapplied to the inner array of electrodes that inhibits charged particlesfrom approaching either of the parallel surfaces. The device alsoincludes a RF voltage source and a DC voltage source. A DC voltage isapplied to the plurality of outer arrays of electrodes. The RF voltage,with a DC superimposed electric field, is applied to the innerelectrodes by applying the DC voltage to each electrode, such that ionswill move between the parallel surfaces within an ion confinement areain the direction of the electric field or have their motion confined toa specific area such that they are trapped in the ion confinement area.Transfer of the ions to another pair of parallel surfaces or throughmultiple pairs of parallel surfaces is allowed through an aperture inone or more of the surfaces.

In another embodiment of the present invention, the electrodes havesignificant relief from the surfaces. Regions of such relief can be usedto alter the electric fields, or also to prevent effects due to chargingof nonconductive regions between electrodes. Such designs haveparticular value in regions where ion confinement is imperfect, such asin reaction regions where ion-molecule or ion-ion reactions result inion products that have m/z values either too high or too low foreffective ion confinement. In such cases just the reaction regions mayrequire electrodes that extend from the surfaces, and in such casesthese regions may have different, often larger, spacing between the twosurfaces.

In another embodiment of the present invention RF potentials having twoor more distinct frequencies and different electric fields areco-applied to the arrays of electrodes on the two surfaces and with apattern of application that creates a pseudopotential that inhibitscharged particles from approaching one or both of the substantiallyparallel surfaces over a substantially greater m/z range than would befeasible with RF potentials of a single frequency.

In another embodiment of the present invention, each central or innerelectrode is replaced by two or more electrodes with adjacent electrodeshaving different phase of the RF applied such that the traps formed forions close to one of the surfaces are substantially reduced, resultingin improved performance such as a reduction of possible trapping effectsor reduction in the m/z range that can be transmitted, particularly whenion currents near the upper limit are being transmitted.

In another embodiment of the present invention, an ion manipulationdevice with electrical breakdown protection is disclosed. The deviceincludes a pair of surfaces including an ion inlet and an ion outlet.The device also includes arrays of electrodes coupled to the surfaces towhich RF potentials are applied to at least one of the surfaces in orderto create a pseudopotential that inhibits charged particles fromapproaching the surfaces. The device further includes simultaneousapplication of DC potentials to control and restrict movement of ions inbetween each pair of surfaces, wherein the surfaces are housed in achamber. At least one electrically insulative shield is coupled to aninner surface of the chamber for increasing a mean-free path between twoadjacent electrodes in the chamber. The ion manipulation device can be,but is not limited to, an ion mobility cyclotron device.

In one embodiment, the at least one insulative shield includes a firstinsulative shield enclosing at least a part of the inlet and a secondinsulative shield enclosing at least a part of the outlet. The firstinsulative and the second insulative shield may be made of, but notlimited, to Teflon, polyether ether ketone (PEEK), or polycarbonate.

In another embodiment, the inner surface is a side plate, and the atleast one insulative shield is coupled to the plate via a sealingmember.

The sealing member is, but not limited to, an O-ring, adhesive, orsealant, and the at least one insulative shield includes electricalfeedthrough housing.

In one embodiment, the device includes a plurality of ion manipulationdevices.

The device with electrical breakdown protection can include a firstinsulation plate between each ion device inside of the chamber. Thefirst insulation plate is made of, but not limited to, ceramic, Teflon,fiberglass, PEEK, or polycarbonate.

The device with electrical breakdown protection can include a top coverlocated above a top ion device in the chamber, and a bottom coverlocated below a bottom ion device. The top cover may include bolt holesfor sealing purposes, and the bottom lid may include a metal plate withan insulation plate embedded on the metal plate.

In one embodiment, an inlet of each device is coupled to an ion source,and an outlet of each device is coupled to a mass spectrometer. The ionsource may be, but is not limited to, an ion funnel or a dual ionfunnel.

In another embodiment of the present invention, an ion manipulationdevice with electrical breakdown protection is disclosed. The deviceincludes a pair of surfaces including an ion inlet and an ion outlet.The device also includes arrays of electrodes coupled to the surfaces towhich RF potentials are applied to at least one of the surfaces in orderto create a pseudopotential that inhibits charged particles fromapproaching the surfaces. The device further includes simultaneousapplication of DC potentials to control and restrict movement of ions inbetween each pair of surfaces, wherein the surfaces are housed in achamber. At least one electrically insulative shield is coupled to aside plate of the chamber via a sealing member for increasing amean-free-path between two adjacent electrodes in the chamber.

In another embodiment of the present invention, an ion manipulationdevice with electrical breakdown protection is disclosed. The deviceincludes a pair of surfaces including an ion inlet and an ion outlet.The device also includes arrays of electrodes coupled to the surfaces towhich RF potentials are applied to at least one of the surfaces in orderto create a pseudopotential that inhibits charged particles fromapproaching the surfaces. The device further includes simultaneousapplication of DC potentials to control and restrict movement of ions inbetween each pair of surfaces, wherein the surfaces are housed in achamber. A first insulative shield encloses at least part of the inletand a second insulative shield encloses at least a part of the outlet.

In another embodiment of the present invention, an ion manipulationdevice with electrical breakdown protection is disclosed. The deviceincludes a pair of surfaces including an ion inlet and an ion outlet.The device also includes arrays of electrodes coupled to the surfaces towhich RF potentials are applied to at least one of the surfaces in orderto create a pseudopotential that inhibits charged particles fromapproaching the surfaces. The device further includes simultaneousapplication of DC potentials to control and restrict movement of ions inbetween each pair of surfaces, wherein the surfaces are housed in achamber. The device also includes a plurality of insulative shields forincreasing a mean-free-path between two adjacent electrodes in thechamber, wherein the plurality of shields includes: i. one or more innersurface insulative shields coupled to one or more side plates of thechamber; and one or more inlet and outlet insulative shields, whereinthe inlet insulative shield encloses at least a part of the inlet, andthe outlet insulative shield encloses at least a part of the outlet.

In another embodiment of the present invention, an ion manipulationdevice to prevent loss of ions is disclosed. The device includes a pairof surfaces and an inner array of electrodes coupled to the surfaces.The device also includes a RF voltage and a DC voltage. The RF and DCvoltages are alternately applied to the inner array of electrodes. Theapplied RF voltage is alternately positive and negative so thatimmediately adjacent or nearest neighbor RF applied electrodes aresupplied with RF signals that are approximately 180 degrees out ofphase.

In one embodiment, the device includes a first outer electrode arraycoupled to the surface and positioned on one side of the inner array ofelectrodes, and a second outer electrode array coupled to the surfaceand positioned on the other side of the inner array of electrodes. Asecond DC voltage is applied to the first and second outer electrodearrays.

The device can include multiple pairs of surfaces, wherein transfer ofthe ions is allowed through an aperture and guided by a series ofelectrodes to move between different pairs of surfaces of the multiplepairs of surfaces.

The DC voltage may be a static or a time-varying DC voltage. In oneembodiment, the time-varying DC voltage is a traveling wave voltage.

In one embodiment, the pair of surfaces is a pair of substantiallyparallel surfaces.

In one embodiment, the array of inner electrodes is contained within andextends substantially along the length of each surface. In oneembodiment, the arrays of outer electrodes are contained within andextend substantially along the length of each surface.

In another embodiment of the present invention, a method of manipulatingions is disclosed. The method includes injecting ions between a pair ofsurfaces. Each pair of surfaces contains an array of inner electrodes.The method also includes applying a RF voltage and a DC voltagealternately to the inner array of electrodes. The applied RF voltage isalternately positive and negative so that immediately adjacent ornearest neighbor RF applied electrodes are supplied with RF signals thatare approximately 180 degrees out of phase.

In another embodiment of the present invention, an ion manipulationdevice to prevent loss of ions is disclosed. The device includes a pairof surfaces and an inner array of electrodes coupled to the surfaces.The device also includes a RF voltage applied to only one of thesurfaces and a DC voltage applied to only the other surface. In oneembodiment, the device includes first outer electrode array coupled tothe surface and positioned on one side of the inner array of electrodes,and a second outer electrode array coupled to the surface and positionedon the other side of the inner array of electrodes, wherein a second DCvoltage is applied to the first and second outer electrode arrays.

In another embodiment of the present invention, a method of manipulatingions is disclosed. The method includes injecting ions between a pair ofsurfaces, wherein each pair of surfaces contains an array of innerelectrodes. The method also includes applying a RF voltage to only oneof the surfaces and a DC voltage to only the other surface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic of a portion of an individual parallel surfacecontaining an arrangement of electrodes for an ion manipulation device,in accordance with one embodiment of the present invention.

FIG. 1B is a schematic of a portion of an ion manipulation device, inaccordance with one embodiment of the present invention.

FIG. 2 is a schematic of a portion of an individual parallel surfacecontaining an arrangement of electrodes, and also showing an ionconfinement area, for an ion manipulation device, in accordance with oneembodiment of the present invention.

FIG. 3A is a schematic of an individual parallel surface containing anarrangement of electrodes for an ion manipulation device, in accordancewith one embodiment of the present invention.

FIG. 3B is a schematic of an ion manipulation device, in accordance withone embodiment of the present invention.

FIG. 4A is a schematic of an ion manipulation device, in accordance withone embodiment of the present invention.

FIG. 4B shows where the ions will be confined when DC and RF potentialsare applied to the device of FIG. 4A, in accordance with one embodimentof the present invention.

FIGS. 5A, 5B, and 5C show simulations for an ion switch in a T-shapedconfiguration of an ion manipulation device, in accordance with oneembodiment of the present invention.

FIG. 6 shows dual polarity trapping regions for ion-ion reactions in anion manipulation device, in accordance with one embodiment of thepresent invention.

FIG. 7 shows simulations of an ion switch in an “elevator” configurationwhere ions are transferred through one or more apertures to move betweendifferent pairs of parallel surfaces in an ion manipulation device, inaccordance with one embodiment of the present invention.

FIG. 8 shows simulations of an ion switch in an “elevator” configurationhaving multiple levels where ions are transferred through one or moreapertures to move between different pairs of parallel surfaces in an ionmanipulation device, in accordance with one embodiment of the presentinvention.

FIG. 9 shows an ion manipulation device implemented as an ion mobilitycyclotron for high resolution separations, in accordance with oneembodiment of the present invention.

FIG. 10 shows an ion mobility device coupled between an array of ionsources and an array of mass spectrometer devices, in accordance withone embodiment of the present invention.

FIG. 11 shows one example of an electrical interface for an ionmanipulation device in a chamber, including a side lid, electricalinsulation housings and electrical feedthroughs, in accordance with oneembodiment of the present invention.

FIG. 12 shows one example of an insulation shield coupled to inlet andoutlet openings of an ion manipulation device inside of a chamber, inaccordance with one embodiment of the present invention.

FIG. 13 shows a plurality of vacuum chambers arranged in a stack forhousing one or more ion manipulation devices, in accordance with oneembodiment of the present invention.

FIG. 14A is a schematic of one surface of an ion manipulation devicewith RF inner electrodes having widths of approximately 0.9 mm and thegap between the electrodes is approximately 0.7 mm, in accordance withone embodiment of the present invention.

FIG. 14B is a schematic of one surface of an ion manipulation devicewith RF inner electrodes, similar to FIG. 14A, having larger widths anda narrower gap between the electrodes, in accordance with one embodimentof the present invention.

FIG. 15A is a schematic of one surface of an ion manipulation devicewith alternating RF and DC inner electrodes having similar widths and agap of approximately 0.3 mm between the electrodes, in accordance withone embodiment of the present invention.

FIG. 15B is a schematic of one surface of an ion manipulation devicewith alternating RF and DC inner electrodes, similar to FIG. 15A, withthe RF electrodes having widths larger than the widths of the DCelectrodes and a gap of approximately 0.2 mm between the electrodes, inaccordance with one embodiment of the present invention.

FIG. 15C is a schematic of one surface of an ion manipulation devicewith alternating RF and DC inner electrodes, similar to FIGS. 15A and15B, with the RF electrodes having widths smaller than the widths of theDC electrodes and a gap of approximately 0.2 mm between the electrodes,in accordance with one embodiment of the present invention.

FIG. 16 shows the effective field, calculated for a range of distancesfrom the midplane (Y=0 mm) to the surface of the device (Y=2.2), withf=1 MHz, V_(RF)=100 V_(0p), and m/z=1000, using the ion manipulationdevices of FIG. 14A (denoted as ‘c1’ on the figure), FIG. 14B (denotedas ‘c2’ on the figure), FIG. 15A (denoted as ‘c3’ on the figure), FIG.15B (denoted as ‘c4’ on the figure), and FIG. 15C (denoted as ‘c5’ onthe figure).

FIGS. 17A and 17B show the effective potential z-profiles for variousoff-board distances ‘h’ using the ion manipulation device of FIG. 14A,with f=1 MHz, V_(RF)=100 V_(0p), and m/z=1000.

FIGS. 18A and 18B show the effective potential profiles along the ionpath, z axis, for various off-board distances using the ion manipulationdevice of FIG. 14B, with f=1 MHZ, V_(RF)=100 V_(0p), and m/z=1000.

FIGS. 19A and 19B show the effective potential z-profiles for variousoff-board distances using the ion manipulation device of FIG. 15A, withf=1 MHZ, V_(RF)=100 V_(0p), and m/z=1000.

FIGS. 20A and 20B show the effective potential z-profiles for variousoff-board distances using the ion manipulation device of FIG. 15B, withf=1 MHZ, V_(RF)=100 V_(0p), and m/z=1000.

FIGS. 21A and 21B show the effective potential z-profiles for variousoff-board distances using the ion manipulation device of FIG. 15C, withf=1 MHZ, V_(RF)=100 V_(0p), and m/z=1000.

FIGS. 22A and 22B show the DC potential z-profiles for various off-boarddistances using the ion manipulation device of FIG. 15A, with potential100 V applied to DC inserts or electrodes.

FIGS. 23A and 23B show the DC potential z-profiles for various off-boarddistances using the ion manipulation device of FIG. 15B, with DCpotential 100 V applied to DC inserts or electrodes.

FIGS. 24A and 24B show the DC potential z-profiles for various off-boarddistances using the ion manipulation device of FIG. 15C, with DCpotential 100 V applied to DC inserts or electrodes.

FIG. 25 is a schematic of a top and bottom surface of an ionmanipulation device with DC only inner electrodes on the top surface andRF only inner electrodes on the bottom surface, in accordance with oneembodiment of the present invention.

FIG. 26A is a schematic of the RF only inner electrode surface, similarto the bottom surface of FIG. 25, with wider RF electrodes.

FIG. 26B is a schematic of the RF only inner electrode surface, similarto FIG. 26A, with narrower RF electrodes.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is directed to devices, apparatuses, and method ofmanipulating ions. The present invention uses electric fields to createfield-defined pathways, traps, and switches to manipulate ions in thegas phase, and with minimal or no losses. Embodiments of the deviceenable complex sequences of ion separations, transfers, path switching,and trapping to occur in the space between two surfaces positioned apartand each patterned with conductive electrodes. In one embodiment, thepresent invention uses the inhomogeneous electric fields created byarrays of closely spaced electrodes to which readily generatedpeak-to-peak RF voltages (V_(p-p)˜100 V; ˜1 MHz) are applied withopposite polarity on adjacent electrodes to create effective potentialor pseudopotential fields that prevent ions from approaching thesurfaces. These ion confining fields result from the combination of RFand DC potentials, with the RF potentials among other roles creating apseudopotential that prevents loss of ions and charged particles overcertain m/z ranges to a surface, and the DC potentials among other rolesbeing used to confine ions to particular defined paths of regionsbetween the two surfaces, or to move ions parallel to the surfaces. Theconfinement functions over a range of pressures (<0.001 torr to ˜1000torr), and over a useful, broad, and adjustable mass to charge (m/z)range. Of particular interest is the ability to manipulate ions that canbe analyzed by mass spectrometers, and where pressures of <0.1 to ˜50torr can be used to readily manipulate ions over a useful m/z range,e.g., m/z 20 to >5,000. This effective potential works in conjunctionwith DC potentials applied to side electrodes to prevent ion losses, andallows the creation of ion traps and/or conduits in the gap between thetwo surfaces for the effectively lossless storage and/or movement ofions as a result of any gradient in the applied DC fields.

In one embodiment, the invention discloses the use of RF and DC fieldsto manipulate ions. The manipulation includes, but is not limited to,controlling the ion paths, separating ions, reacting ions, as well astrapping and accumulating the ions by the addition of ions to thetrapping region(s). The ion manipulation device, which may be referredto as an “ion conveyor” or Structure for Lossless Ion Manipulation(SLIM), uses arrays of electrodes on substantially parallel surfaces tocontrol ion motion. Combinations of RF and DC potentials are applied tothe electrodes to create paths for ion transfer and ion trapping. Theparallel surfaces may be fabricated using, but not limited to, printedcircuit board technologies or 3D printing.

FIG. 1A is a schematic of a portion of an individual parallel surface100 containing a first and second array of outer electrodes 120 and anarray of inner electrodes 130 for an ion manipulation device, inaccordance with one embodiment of the present invention. The array ofinner electrodes 130 is contained within and extends substantially alongthe length of the surface 100. The array of outer electrodes 120,positioned on either side of the inner electrodes 130, is also containedwithin and extends substantially along the length of the surface 100.

FIG. 1B is a schematic of a portion of an ion manipulation device 200,in accordance with one embodiment of the present invention. The device200 includes a pair of substantially parallel surfaces 210 and 215. Eachsurface contains an array of inner electrodes 230 and a first and secondarray of outer electrodes 220. The arrays of outer electrodes 220 arepositioned on either side of the array of inner electrodes 230. Thearrays of electrodes 220 and 230 are contained within and extendsubstantially along the length of each parallel surface 210 and 215. Thearrangement of electrodes on the opposing surfaces can be identical aswell as the electric field applied. Alternately, either the detailedelectrode arrangements or the electric fields applied can be differentin order to affect ion motion and trapping between the device.

The portion of the device 200 also includes a RF voltage source and DCvoltage sources (not shown). In one embodiment, the DC voltages areapplied to the first and second outer array of electrodes 220. The RFvoltage, of opposite polarity upon adjacent electrodes, with asuperimposed DC electric field, is applied to the inner array ofelectrodes 220. In the arrangement of FIG. 2, with the RF and DC fieldsapplied as such, ions either move between the parallel surfaces 210 and215 within an ion confinement area in the direction of the electricfield or can be trapped in the ion confinement area depending on the DCvoltages applied.

In one embodiment, the RF on at least one inner electrode is out ofphase with its neighboring inner electrode. In another embodiment, eachinner electrode is 180 degrees out of phase with its neighboring innerelectrode to form a pseudopotential that inhibits charged particles fromapproaching either of the parallel surfaces. In another embodiment eachinner electrode is replaced by two or more electrodes to which RF isapplied to each and with one or more the electrodes being out of phasewith its neighboring inner electrodes.

The electric field also allows the ions to move in a circular-shaped ora rectangular-shaped path, to allow the ions to make more than onetransit. Stacks of cyclotron stages can be used with the device 200.Arrangements with cyclotrons, where the ions traverse a circular path,will allow very high-resolution mobility separations with small physicalsize.

In one embodiment, the array of inner electrodes 220 comprises at leasttwo electrodes on the pair of parallel surfaces 210 and 215. The firstouter array of electrodes and the second outer array of electrodes 220may each comprise at least two electrodes on the pair of parallelsurfaces 210 and 215.

In one embodiment the RF is simultaneously applied with DC potentials tothe electrodes 220, and in another embodiment the RF applied to adjacentouter electrodes has opposite polarity.

In one embodiment the space between the surfaces 210 and 215 may includea gas or otherwise vaporized or dispersed species that ions react with.

In one embodiment the electrodes 220 are augmented by an additional setof electrodes further displaced from the central electrodes that has DCpotentials applied that are opposite in polarity to allow theconfinement or separation of ions of opposite polarity.

The device 200 can be coupled to other devices, apparatuses and systems.These include, but are not limited to, a charge detector, an opticaldetector, and/or a mass spectrometer. The ion mobility separationpossible with the device 200 can be used for enrichment, selection,collection and accumulation over multiple separations of any mobilityresolved species.

The device 200 may be used to perform ion mobility separations.

In one embodiment, the RF frequency applied to the electrodes 230 isbetween 0.1 kHz and 50 MHz, and the electric field is between 0 and 5000volts/mm.

In one embodiment, the electrodes 220 and 230 are perpendicular to atleast one of the surfaces and may comprise a thin conductive layer onthe surfaces 210 and 215.

The device 200 can include multiple pairs of substantially parallelsurfaces, allowing transfer of the ions through an aperture to movebetween different pairs of parallel surfaces.

The electrodes on the pair of surfaces 210 and 215 can form one of manydifferent configurations. In one embodiment, the surfaces 210 and 215form a substantially T-shaped configuration, allowing ions to beswitched at a junction of the T-shaped configuration. In anotherembodiment, the surfaces 210 and 215 form a substantially Y-shapedconfiguration, allowing ions to be switched at a junction of theY-shaped configuration. In another embodiment, the surfaces 210 and 215form a substantially X-shaped or cross-shaped configuration, allowingions to be switched at a junction or one or more sides of the X-shapedconfiguration. In another embodiment, the surfaces 210 and 215 form asubstantially multidirectional shape, such as an asterisk (*)-shapedconfiguration, with multiple junction points, allowing ions to beswitched at a junction to one or more sides of the configuration.Devices may be constituted from any number of such elements.

The electrodes on the surfaces can have any shape, not being limited tothe rectangular shapes such as in FIG. 1. For example, the electrodescan be round, have ellipse or oval shapes, or be rectangles with roundedcorners.

FIG. 2 is a schematic of an individual parallel surface 300 containingan arrangement of electrodes 320 and 330 with an ion confinement area340 for an ion manipulation device, in accordance with one embodiment ofthe present invention. Static DC voltages may be applied to the outerelectrodes 320 with RF applied to the inner electrodes 330. Each centralelectrode can have RF applied out of phase with its neighboringelectrode.

A DC or other electric field is superimposed on the RF and applied tothe inner electrodes 330 to move ions through the device of FIG. 2, inaddition to successively lower voltages applied on each outer electrode320—moving from left to right or alternatively from right to left,depending on the polarity and the desired direction of motion. Thiselectric field forces ions to the right, while the RF and DC fields alsoconfine ions to a central region of the device as shown. Voltagepolarities can be changed to allow manipulation of both negative andpositive ions.

FIG. 3A is a schematic of an individual parallel surface 400 containingan arrangement of electrodes for an ion manipulation device, inaccordance with one embodiment of the present invention. The surface 400includes electrodes 450 that are individually programmable by a DCvoltage, electrodes 430 associated with a negative RF voltage, andelectrodes 435 associated with a positive RF voltage—where negative andpositive RF refers to the phase of the RF waveform.

FIG. 3B is a schematic of an ion manipulation device 500, in accordancewith one embodiment of the present invention. The ion manipulationdevice 500 includes substantially parallel surfaces 510 and 515 that aresimilar to the surface 400 of FIG. 3A. The device 500 includeselectrodes 550 that are individually programmable by a DC voltage,electrodes 530 associated with a negative RF voltage, and electrodes 535associated with a positive RF voltage. In this arrangement, ions areconfined between the surfaces 510 and 515. The ions move in thedirection defined by an electric field.

FIG. 4A is a schematic of an ion manipulation device, in accordance withone embodiment of the present invention. The central or inner electrodeshave RF fields applied with opposite polarity to adjacent electrodes tocreate fields that prevent ions from closely approaching the surfaces.Ions are moved according to their mobilities under DC fields applied tothe outer electrodes.

FIG. 4B shows the trapping volume of ions between the surfacescontaining electrodes of an ion manipulation device, in accordance withone embodiment of the present invention. Both positive and negativecharged ion particles are confined in overlapping areas of the ionmanipulation device. This can be accomplished using multiple arrays ofouter electrodes and applying both RF and DC potentials.

The devices of the present invention provide for at least the following:lossless (a) linear ion transport and mobility separation, (b) iontransport around a corner (e.g., a 90 degree bend), (c) ion switches todirect ions to one of at least two paths, (d) ion elevators fortransporting ions between different levels of multilevel ionmanipulation devices, (e) ion traps for trapping, accumulation, andreaction of ions of one polarity. These devices can be combined tocreate a core module for more complex ion manipulation devices such asan ion mobility cyclotron. In one implementation, integrating severalmodules will allow fabrication of a single level device that will enablethe separation of ions over periods on the order of 0.1 to 10 secondswhile achieving resolutions of up to approximately 1000 for species overa limited range of mobilities. The range of mobilities, and thefractions of the total biomolecule ion mixture that can be separated,decreases as the resolution is increased. Thus, an ion mobilitycyclotron module can provide a useful and targeted separation/analysiscapability—where information is desired for a limited subset of species.

The integrated device can consist of a stack of modules each covering adifferent portion of the full mobility spectrum. In combination, theyprovide separations that cover the full range of ion mobilities neededfor a sample, while at the same time making efficient use of all theions from the sample. The integrated device can draw upon the ionswitch, elevator, and trap components to provide a low resolutionseparation that partitions ions from the sample into fractions that aredelivered to different cyclotrons using the ion elevator.

FIGS. 5A, 5B, and 5C show simulations of an ion switch in a T-shapedconfiguration of an ion manipulation device, in accordance with oneembodiment of the present invention. These ion paths can be controlledusing switch elements. As shown in FIGS. 5A, 5B, and 5C, the ion pathcan be dynamically or statically changed by modifying the electrodearrangement of the device and/or varying the RF and DC voltages. Theions can be switched at a junction as shown in FIG. 5A, move in astraight path as shown in FIG. 5B, and/or curve or bend around a cornerat the junction as shown in FIG. 5C. Alternatively, the pair of parallelsurfaces of the device can form other configurations such as, but notlimited to, Y-shaped configurations, X-shaped or cross-shapedconfigurations, and other multidirectional shapes.

FIG. 6 shows dual polarity trapping regions for ion-ion reactions in anion manipulation device, in accordance with one embodiment of thepresent invention. Different polarity of ions, positive and negative,can be trapped at the same time in at least partially overlappingphysical volumes between the two surfaces of the device using multiplesets of electrodes and applying both RF and DC potentials. Additional RFor DC potentials can be applied to heat and excite either the positiveor negatively charged ions in order to change the reaction rate orreaction products.

FIG. 7 shows simulations of an ion switch in an “elevator” configurationwhere ions are transferred through one or more apertures to move betweendifferent pairs of parallel surfaces in an ion manipulation device, inaccordance with one embodiment of the present invention. This allowsmulti-dimensional ion manipulation using the ion manipulation device. Insome embodiments additional electrodes are added to increase theefficiency of transfer between different levels, including electrodeswith DC and/or RF potentials with different polarities on adjacentelectrodes.

FIG. 8 shows simulations of an ion switch in an “elevator” configurationhaving multiple levels where ions are transferred through one or moreapertures to move between different pairs of parallel surfaces in an ionmanipulation device, in accordance with one embodiment of the presentinvention.

FIG. 9 is a schematic showing an ion manipulation device implemented asan ion mobility cyclotron. Ions entering from the ion source areinitially trapped before a first low resolution separation. Separatedions of interest are trapped and then injected for cyclotronseparations, potentially achieving resolutions greater than 1000. Theswitching points direct ions to one of at least two paths. All fourpoints—the switching points and the bends—are where changes in therotating DC electric field can be applied to create the cyclotronmotions.

FIG. 10 shows an ion mobility device coupled between an array of ionsources and an array of mass spectrometer devices, in accordance withone embodiment of the present invention. As shown in FIG. 10, thepresent invention also enables multiplexed sample analyses using anarray of ion sources and multiple ion separations in parallel—separatedduring travel through the device—and detected using an array of highspeed, high dynamic range time-of-flight (TOF) mass spectrometers (MS).

The pair of surfaces of the ion manipulation device can be housed in avacuum chamber. In one embodiment, at least one electrically insulativeshield is coupled to an inner surface of the chamber for increasing amean-free-path between two adjacent electrodes in the chamber.

FIG. 11 shows one example of an electrical interface for an ionmanipulation device in a chamber, including a side lid 610, electricalinsulation housings 600 and electrical feedthroughs 620, in accordancewith one embodiment of the present invention. The side lid is made of anonconductive material. The bottom or flange side 605 of the electricalinsulation housing 600 includes a sealing member to isolate themean-free-path between adjacent electrodes on the chamber side of thefeedthroughs 620. The sealing member is, but not limited to, an O-ring,an adhesive, or a sealant. The flange 605 is coupled to the side lid 610via the sealing member.

FIG. 12 shows one example of an insulation shield 700 coupled to inletand outlet openings of an ion manipulation device inside of a chamber710, in accordance with one embodiment of the present invention. Theinsulation shield 700 is made of, but not limited to, Teflon, PEEK, orpolycarbonate.

FIG. 13 shows a plurality of vacuum chambers 810 arranged in a stack 800for housing one or more ion manipulation devices, in accordance with oneembodiment of the present invention. Although six chambers are shown inFIG. 13, it should be noted that the stack 800 is not limited to anyspecific number of chambers.

The chambers 810 include at least one inlet and at least one outlet. Theinlet may be coupled to an ion source interface such as, but not limitedto, an ion funnel or a dual ion funnel 820. The outlet may be coupled toa mass spectrometer or analyzer directly or indirectly via another iondevice 830 for manipulating and/or focusing ions. In the embodiment ofFIG. 13, the bottom chamber of the stack 800 is coupled through an ionfunnel chamber 820 to a mass spectrometer 830 at the outlet. In theinlet, two ion funnel chambers 820 are connected as the ion sourceinterface. One or more of the chambers 810 can include a sensor such as,but not limited to, a pressure sensor.

FIG. 14A is a schematic of one surface of an ion manipulation device1400 with RF inner electrodes 1420 having widths of approximately 0.9 mmand the gap between the electrodes is approximately 0.7 mm. The surfacealso includes DC outer electrodes 1410. At least one RF voltage isapplied to the RF inner electrodes 1420 and at least one DC voltage isapplied to the DC outer electrodes 1410.

FIG. 14B is a schematic of one surface of an ion manipulation device1450 with RF inner electrodes 1470, similar to FIG. 14A, having largerwidths and a narrower gap between the electrodes 1470. The surface alsoincludes DC outer electrodes 1460. As with FIG. 14A, a RF voltage orvoltages are applied to the RF inner electrodes 1470 and a DC voltage orvoltages are applied to the DC outer electrodes 1460.

In another embodiment, as shown in FIGS. 15A-C, RF and DC voltages arealternately applied to the inner array of electrodes, and the applied RFvoltage is alternately positive and negative so that immediatelyadjacent or nearest neighbor RF applied electrodes are supplied with RFsignals that are approximately 180 degrees out of phase.

FIG. 15A is a schematic of one surface of an ion manipulation device1500 with alternating RF inner electrodes 1520 and DC inner electrodes1530. In this example, the electrodes 1520 and 1530 having similarwidths of approximately 0.5 mm and a gap of approximately 0.3 mm betweenthe electrodes 1520 and 1530. The surface also includes outer electrodes1510 adjacent or positioned on either side of the inner electrodes 1520and 1530. DC voltages are applied to the outer electrodes 1510. Itshould be noted that the widths or diameters of the electrodes, as wellas the gap dimensions between each electrode, may vary by length.

FIG. 15B is a schematic of one surface of an ion manipulation devicewith alternating RF inner electrodes 1570 and DC inner electrodes 1575,similar to FIG. 15A, with the RF electrodes having widths larger thanthe widths of the DC electrodes and a gap of approximately 0.2 mmbetween the electrodes. In this example, the RF electrodes have a widthof approximately 0.9 mm, and the DC electrodes have a width ofapproximately 0.3 mm. The surface also includes outer electrodes 1560adjacent or positioned on either side of the inner electrodes 1570 and1575. DC voltages are applied to the outer electrodes 1560.

FIG. 15C is a schematic of one surface of an ion manipulation device1580 with alternating RF inner electrodes 1592 and DC inner electrodes1595, similar to FIGS. 15A and 15B. In this example, the RF electrodes1592 have widths smaller than the widths of the DC electrodes 1595. Thewidth of the RF electrodes 1592 is approximately 0.3 mm, and the widthof the DC electrodes 1595 is approximately 0.9 mm. The surface includesa gap of approximately 0.2 mm between each inner electrode 1592 and1595.

The ion manipulation device of FIGS. 15A-15C may be coupled, but notlimited to, a charge detector, an optical detector, and a massspectrometer. In one embodiment, the ion manipulation device is used toperform ion mobility separations.

The DC voltages on the inner electrodes of FIGS. 15A-15C is a static ortime-varying DC voltage. The time-varying voltage may be a travelingwave voltage.

The ion manipulation device of FIGS. 15A-15C includes a pair ofsurfaces. The pair of surfaces are substantially parallel orsubstantially planar. In one embodiment, the surfaces are not flat.

FIG. 16 shows the effective field, calculated for a range of distancesfrom the midplane (Y=0 mm) to the surface of the device (Y=2.2 mm), withf=1 MHz, V_(RF)=100 V_(0p), and m/z=1000, using the ion manipulationdevices of FIG. 14A (denoted as ‘c1’ on the figure), FIG. 14B (denotedas ‘c2’ on the figure), FIG. 15A (denoted as ‘c3’ on the figure), FIG.15B (denoted as ‘c4’ on the figure), and FIG. 15C (denoted as ‘c5’ onthe figure). An effective field of E_(y)≈100 V/cm was achievable atapproximately 1.6 mm or 0.6 mm from the surface of the ion manipulationdevice, where y_(max) is approximately 2.2 mm.

FIGS. 17A and 17B show the effective potential z-profiles for variousoff-board distances ‘h’ using the ion manipulation device of FIG. 14A,with f=1 MHz, V_(RF)=100 V_(0p), and m/z=1000. Smooth profiles areobtained for h>0.5 mm.

FIGS. 18A and 18B show the effective potential z-profiles for variousoff-board distances from 0.1 mm to 1.2 mm using the ion manipulationdevice of FIG. 14B, with f=1 MHZ, V_(RF)=100 V_(0p), and m/z=1000.

FIGS. 19A and 19B show the effective potential z-profiles for variousoff-board distances using the ion manipulation device of FIG. 15A, withf=1 MHZ, V_(RF)=100 V_(0p), and m/z=1000.

FIGS. 20A and 20B show the effective potential z-profiles for variousoff-board distances using the ion manipulation device of FIG. 15B, withf=1 MHZ, V_(RF)=100 V_(0p), and m/z=1000. The profiles are close toideal when h>0.5 mm, where E_(y) is >approximately 100 V/cm.

FIGS. 21A and 21B show the effective potential z-profiles for variousoff-board distances using the ion manipulation device of FIG. 15C, withf=1 MHZ, V_(RF)=100 V_(0p), and m/z=1000. In this example, the profileswere less than ideal, as the effective fields were weak.

FIGS. 22A and 22B show the DC potential z-profiles for various off-boarddistances using the ion manipulation device of FIG. 15A, with f=1 MHZ,V_(RF)=100 V_(0p), and m/z=1000. Uniform profiles were obtained at h>1.2mm, with a penetration of 43% of the DC potential into the centralvolume.

FIGS. 23A and 23B show the DC potential z-profiles for various off-boarddistances using the ion manipulation device of FIG. 15B, with f=1 MHZ,V_(RF)=100 V_(0p), and m/z=1000. The narrower DC electrodes in thisexample led to a reduced penetration of approximately 27% to the center.

FIGS. 24A and 24B show the DC potential z-profiles for various off-boarddistances using the ion manipulation device of FIG. 15C, with f=1 MHZ,V_(RF)=100 V_(0p), and m/z=1000. The wider DC electrodes in this exampleled to an increased penetration of approximately 55% to the center.

FIG. 25 is a schematic of a top surface 1600 and a bottom surface 1650of an ion manipulation device with DC only inner electrodes 1620 on thetop surface 1600 and RF only inner electrodes 1670 on the bottom surface1650. The top surface 1600 includes outer electrodes 1610 on either sideof the inner electrodes 1620. Similarly, the bottom surface 1650 alsoincludes outer electrodes 1660 on either side of the inner electrodes1670. In this embodiment or example, a RF voltage is applied to only theinner electrodes 1670 of the bottom surface 1650, and only a DC voltageis applied to the inner electrodes 1620 of the top surface 1600. Itshould be noted that the top surface can have “RF only” innerelectrodes, while the bottom surface has “DC only” inner electrodes. ADC voltage is applied to the outer electrodes of each surface 1600 and1650. The DC voltage applied to the outer electrodes may be different orthe same voltage applied to the DC only inner electrodes.

FIG. 26A is a schematic of the RF only inner electrode surface 1700,similar to the bottom surface of FIG. 25, with wider RF inner electrodes1720. The surface 1700 also includes a first and second array of outerelectrodes 1710. In this example, the RF electrodes or strips 1720 areapproximately 0.8 mm wide with approximately 0.4 mm spaces between thestrips.

FIG. 26B is a schematic of the RF only inner electrode surface 1750,similar to FIG. 26A, with narrower RF electrodes 1770. The surface 1750also includes a first and second array of outer electrodes 1760. In thisexample, the RF electrodes or strips 1770 are approximately 0.4 mm widewith approximately 0.4 mm spaces between the strips.

The ion manipulation devices, particularly the embodiments shown inFIGS. 15A-C, 25 and 26, address the need for reduced complexity, controlelectronics, and expense of power supplies needed to enable complexsequences of ion manipulations. This is mainly due to the separation ofelectrodes to which RF and DC voltages are applied.

The devices also enable the use of longer path length ion mobilityseparations and/or other manipulations, providing much higherresolutions, as large differences in electric fields are notrequired—the potential needed for, for example, separations typicallyincrease in proportion with the length of the ion manipulation path. Thedevices cover the full mobility range, which does not require a limitedmobility range as would be required for separations in a cyclotron orother receptive path of limited length.

EXAMPLE

The following examples serve to illustrate certain embodiments andaspects of the present invention and are not to be construed as limitingthe scope thereof

A device, as shown in FIG. 1B, was used to manipulate ions injected froman external ESI source. Simulations were performed to refine the designof the device; e.g. electrode sizes and spacing between the planarsurfaces were adjusted. Boards were fabricated with electrode regions totest capabilities that included efficient ion transportation, ionmobility separations, ion trapping, and ion switching betweenalternative corridors or paths.

In one test, ions were introduced from the external ESI source andinjected into one of the ion corridors at a pressure of ˜4 torr. RFfrequencies of approximately 1.4 MHz and 140 Vp-p were applied to createrepulsive fields to confine ions within the ion corridors between theopposing board surfaces. The RF fields were combined with DC for furtherconfinement to the corridors and also to move the ions along thecorridors based upon their ion mobilities. Separate electrodes were usedto measure ion currents at various locations and evaluate iontransmission efficiency through different areas of the device. Initialmeasurements showed that ions can be efficiently introduced into suchdevices, as well as transported through them with minimal losses.

The device of the present invention, including its various embodiments,can be manufactured at very low cost and is very flexible, allowingapplication to many different areas in mass spectrometry. As oneexample, the device can be fabricated and assembled using printedcircuit board technology and interfaced with a mass spectrometer. Thedevice can also be lossless. Ion mobility separation and complex ionmanipulation strategies can be easily implemented with the device.

The device of the present invention, including its various embodiments,can be altered in its performance by the use of electrodes that havesignificant thickness and thus substantial relief from one or both ofthe surfaces. The thickness can vary between electrodes, and individualelectrodes can have variable thickness. These electrodes can be used tocreate electric fields not practical for very thin electrodes (e.g.surface deposited such as on conventional printed circuit boards).Regions of devices with such electrodes have particular value whenincomplete or inefficient ion confinement may occur, such as for verylow or high m/z ions created by reactions that can provide awell-controlled electric field and prevent degraded performance fromdistorted electric fields due to the charging of surfaces betweenelectrodes.

Embodiments of the present invention can improve and extend analysiscapabilities in, for example, proteomics, metabolomics, lipidomics,glycomics, as well as their applications to a broad range of biologicaland chemical measurements and applicable research areas. Utilization ofthe ion manipulation device can lead to faster, cheaper, and moresensitive measurements relevant to understanding chemical,environmental, or biological systems. The present invention enablesMS-based approaches involving complex ion manipulations in the gas phasecapable of augmenting or completely displacing conventional liquid phaseapproaches. The present invention also enables separations and other ionmanipulations over extended periods in a nearly lossless fashion. Thesecapabilities lead to very fast and high resolution gas phase separationsof ions.

The present invention has been described in terms of specificembodiments incorporating details to facilitate the understanding of theprinciples of construction and operation of the invention. As such,references herein to specific embodiments and details thereof are notintended to limit the scope of the claims appended hereto. It will beapparent to those skilled in the art that modifications can be made inthe embodiments chosen for illustration without departing from thespirit and scope of the invention.

We claim:
 1. An ion manipulation device to prevent loss of ionscomprising: a. a pair of surfaces; b. an inner array of electrodescoupled to the surfaces; and c. a RF voltage and a DC voltage beingalternately applied to the inner array of electrodes, wherein theapplied RF voltage is alternately positive and negative so thatimmediately adjacent or nearest neighbor RF applied electrodes aresupplied with RF signals that are approximately 180 degrees out ofphase.
 2. The device of claim 1 further comprising a first outerelectrode array coupled to the surface and positioned on one side of theinner array of electrodes, and a second outer electrode array coupled tothe surface and positioned on the other side of the inner array ofelectrodes.
 3. The device of claim 2 wherein a second DC voltage isapplied to the first and second outer electrode arrays.
 4. The device ofclaim 1 further comprising multiple pairs of surfaces, wherein transferof the ions is allowed through an aperture and guided by a series ofelectrodes to move between different pairs of surfaces of the multiplepairs of surfaces.
 5. The device of claim 1 wherein the device iscoupled to at least one of the following: a charge detector, an opticaldetector, and a mass spectrometer.
 6. The device of claim 1 wherein thedevice is used to perform ion mobility separations.
 7. The device ofclaim 1 wherein the DC voltage is a static or time-varying DC voltage.8. The device of claim 7 wherein the time-varying DC voltage is atraveling wave voltage.
 9. The device of claim 1 wherein the surfacesare one of the following: substantially planar, substantially parallel,and not flat.
 10. An ion manipulation device comprising: a. a pair ofsubstantially parallel surfaces; b. an array of inner electrodescontained within, and extending substantially along the length of, eachparallel surface; c. a first outer array of electrodes and a secondouter array of electrodes, each positioned on either side of the innerelectrodes, contained within, and extending substantially along thelength of each parallel surface; and d. a RF voltage and a first DCvoltage being alternately applied to the inner array of electrodes,wherein the applied RF voltage is alternately positive and negative sothat immediately adjacent or nearest neighbor RF applied electrodes aresupplied with RF signals that are approximately 180 degrees out ofphase; and e. a second DC voltage applied to the first and second outerelectrode arrays.
 11. The device of claim 10 further comprising multiplepairs of surfaces, wherein transfer of the ions is allowed through anaperture and guided by a series of electrodes to move between differentpairs of surfaces of the multiple pairs of surfaces.
 12. The device ofclaim 11 wherein the surfaces are one of the following: substantiallyplanar, substantially parallel, and not flat.
 13. The device of claim 10wherein the device is coupled to at least one of the following: a chargedetector, an optical detector, and a mass spectrometer.
 14. The deviceof claim 10 wherein the device is used to perform ion mobilityseparations.
 15. The device of claim 10 wherein the first DC voltage isa static or time-varying DC voltage.
 16. The device of claim 15 whereinthe time-varying DC voltage is a traveling wave voltage.
 17. A method ofmanipulating ions comprising: a. injecting ions between a pair ofsurfaces, wherein each pair of surfaces contains an array of innerelectrodes; and b. applying a RF voltage and a DC voltage alternately tothe inner array of electrodes, wherein the applied RF voltage isalternately positive and negative so that immediately adjacent ornearest neighbor RF applied electrodes are supplied with RF signals thatare approximately 180 degrees out of phase.
 18. The method of claim 17wherein each pair of surfaces further contains a first outer electrodearray coupled to the surface and positioned on one side of the innerarray of electrodes, and a second outer electrode array coupled to thesurface and positioned on the other side of the inner array ofelectrodes.
 19. The method of claim 18 further comprising applying asecond DC voltage to the first and second outer electrode arrays. 20.The method of claim 17 wherein the DC voltage is a static ortime-varying DC voltage.
 21. The method of claim 20 wherein thetime-varying DC voltage is a traveling wave voltage.
 22. An ionmanipulation device to prevent loss of ions comprising: a. a pair ofsurfaces; b. an inner array of electrodes coupled to the surfaces; andc. a RF voltage applied to only one of the surfaces, and a DC voltageapplied to only the other surface.
 23. The device of claim 22 furthercomprising a first outer electrode array coupled to the surface andpositioned on one side of the inner array of electrodes, and a secondouter electrode array coupled to the surface and positioned on the otherside of the inner array of electrodes, wherein a second DC voltagesource is applied to the first and second outer electrode arrays. 24.The device of claim 22 wherein the DC voltage is a static ortime-varying DC voltage.
 25. The device of claim 24 wherein thetime-varying DC voltage is a traveling wave voltage.
 26. A method ofmanipulating ions comprising: a. injecting ions between a pair ofsurfaces, wherein each pair of surfaces contains an array of innerelectrodes; b. applying a RF voltage to only one of the surfaces; and c.applying a DC voltage to only the other surface.
 27. The method of claim26 wherein each pair of surfaces further contains a first outerelectrode array coupled to the surface and positioned on one side of theinner array of electrodes, and a second outer electrode array coupled tothe surface and positioned on the other side of the inner array ofelectrodes, wherein a second DC voltage is applied to the first andsecond outer electrode arrays.
 28. The method of claim 27 wherein the DCvoltage is a static or time-varying DC voltage.
 29. The method of claim28 wherein the time-varying DC voltage is a traveling wave voltage.